Weft stop motion for loom



Nov. 29, 1960 F. w. PAUL EIAL WEF'I STOP uonon FOR 1.00:!

3 Sheets-Sheet 1 Filed Oct. 17. 1958 INVENTORS FREDERICK W. PAUL VICTOR E SEPAVICH ATTORNEY 1960 I I F. w. PAUL EI'AL 2,962,056

WEFT STOP MOTION FOR LOOM Filed Oct. 17. 1958 3 Sheets-Sheet 2 INVENTORS FREDERICK W. PAUL VICTOR F. SEPAVICH ATTORNEY WEFT STOP MOTION FOR LOOM Frederick W. Paul, Holden, and Victor F. Sepavich, Worcester, Mass., assignors to Crompton & Knowles Corporation, Worcester, Mass., a corporation of Massachusetts Filed Oct. 17, 1958, Ser. No. 767,997 9 Claims. (Cl. 139-336) This invention relates to improvements in weft stop mot ons for looms and it is the general object of the invention to provide means for automatically reversing the loom to return the lay to its back center position incident to stopping of the loom by a weft fault. I

In the operation of the usual weft stop motion the loom is generally stopped slightly before the lay reaches front center. The lay then remains in this position until the weaver can go to the loom to correct the fault. Under such conditions it is necessary for the weaver to reverse the loom by hand until the lay has reached approximately its back center position with the warp shed open so that the defective weft can be removed. It is an important object of the present invention to provide electrical control means for the loom operating in such manner that after the loom has been stopped by the weft stop motion circuits will be brought into play to reverse the loom until the lay is approximately at its back center position so that when the weaver reaches the loom the lay will already be in the right position to permit correction of the weft fault. I I I h i When the weft defect has been corrected there will ordinarily be no weft in the shed to support the fork of the weft stop motion so that when the loom is restarted the dagger of the stop motion will tend to be in down position where it can again stop the loom. In theordinary weft stop motion this condition is taken care of by a shield which is automatically moved up to shielding position to prevent the dagger from effecting a second, unwanted and unnecessary loom stoppage. It is a further object of the invention to provide means which prevent this second unwanted and unnecessary stoppage even though the dagger be down and rocks the knockoff lever of the weft stop motion when the loom is restarted. Two forms of control for this feature of the invention are set forth one of which operates automatically by a control exercised through an electric relay and the other atent O of which is controlled manually by the weaverwhen he presses the start button for the loom.

In order to make certain that the loom has come, to a full stop before the automatic reversing means can come into action it is a still further object of the invention to provide time delaying means which requires a lapse of a short time interval between stoppage of the loom and the automatic reversal of the lay. This delay as set forth hereinafter is effected by an electric capacitor which is discharged when the loom is stopped but requires recharging before the part of the electric circuit means which effects reversal can be energized.

It is another object of the invention to provide improved driving and reversing mechanisms for a loom including primary and secondary clutch means the first only of which is energized during normal loom running conditions and the second only of which is energized when the lay is to be reversed. The loom has a primary driving pulley which will run continuously during any period assigned to loom operation and this pulley is shaft and in this way reverse the crankshaft.

lever 17 pivoted at 18 to the support 14.

N'CC

.clutch deenergized so that the gear and pulley unit can be caused by the secondary clutch to reverse the jack When the loom has been turned sufliciently to cause the lay to reach its back center position a loom operated timer switch in the electric circuit means will deenergizethe secondary clutch and the electromagnetic brake of the loom will then come into action to stop and 'hold the loom in a position with the lay at back center.

In other that the invention may be clearly understood reference is made to the accompanying drawings which illustrate by way of example two embodiments of the invention and in which:

Fig. 1 is a side elevation partly in section of a loom having the invention applied thereto,

Fig. 2 is an enlarged plan view looking in the direction of arrow 2, Fig. 1.

Fig. 3 is an enlarged vertical section on line 3-3, of

Fig. 1, showing details of the jack shaft,

Fig. 4 is an enlarged vertical section on line 44, of Fig. 1, showing the drive for the rotary switches,

Fig. 5 is an enlarged vertical section on line 44, of Fig. 2, showing part of the electric connections for the primary clutch, i

Fig. 6 is a fragmentary detailed elevation lookingin the direction of arrow 6, Fig. 5, showing the lower part of the three collector rings for the electric connections with the primary switch, i Fig. 7 is a d.agrammatic view of electric circuits used in conn ectiori with the invention, I

Fig. 8 is a detailed view showing part of the knockoff lever and the electric switches which it controls, and

forwardly, passing successively during normal running from back center shown in dotted lines Fig. 1 through bottom center to front center shown in full lines to top center and then to back center to complete one beat of the loom. The loom has a lay driving top crankshaft 4 normally turning clockwise, Fig. 1, and an oppositely fturning bottom shaft 5. Upper and lower gears 6 and 7 secured to the top and bottom shafts respectively cause the top shaft to turn twice as fast as the bottom shaft The lay has a reed 8 and a laybeam 9 formed atjor near its lengthwise center with a well 10 to receive a weft fork 11 of usual construction and operation. The fork -is pivotally connected by a link 12 to a dagger 13 pivotally mounted on the lay' and slidable along the top' surface of a support 14 secured to the breastbeam 15 of the loom. When the lay is in its rearward position the dagger is up on a cam 16 secured to the support and the fork is lifted so that the weft laid by the shuttle S can get under the fork. If as the lay moves forwardly the weft has been properly laid by the shuttle it will be under the fork and hold the latter up and the dagger will be held above the support and pass over a knockofl? If on'the other hand the weft is too slack or is broken it cannot hold the fork raised and as the lay advances the fork will drop in the well and the dagger will engage lever 17 and rock it in a counterclockwise direction, Fig. 1. This will be the condition for loom stoppage, as will be described hereinafter. A spring 19 acts to return lever 17 to itsnormal position as soon as the dagger lose's engagem'ent with the lever due to its angular motion around pivot 18. The weft fork is of usual form and various well known details of its construction have been omitted.

The driving mechanism for the loom includes an electric motor M mounted on a fixed bracket 20 of the loom. The motor has a pulley 21 driving a belt 22 trained over and driving a primary driving pulley 23. The motor and pulley run continuously during a period of operation assigned to weaving, that is, they do not stop under ordinary loom stoppage conditions.

The primary pulley turns freely on a jack shaft 25 suitably mounted for rotation in bearing means 26 mounted on a stand fixed to the loom. A driving pinion 30 fixed to the jack shaft meshes with gear 6 on the crankshaft 4. When the jack shaft is turned it drives the crankshaft which in turn, by its connectors, one of which is shown at 32, moves the lay. During loom operation the jack shaft will ordinarily turn counterclockwise, Fig. 1.

Referring more particularly to Figs. 2 and 3, the jack shaft 25 turns in bearings 35 and 36 and has secured on the outer end thereof by nut 37 the hub 38 of a primary clutch disk 39 held to the hubby screws 40. The disk 39 is made of magnetic material to be attracted by a primary electromagnetic clutch 41 secured at 42 to the primary pulley 23. Pulley 23 has a hub 43 turning freely on one of the steps of the jack shaft 25 and has secured to it at 44 a plate or disk 45 to which is secured a secondary electromagnetic clutch 46. The primary pulley 23 is thus seen to have secured to it and turning with it whenever motor M is turning the primary and secondary electromagnetic clutches.

A small gear 50 turns freely on another step of the jack shaft and has secured to it a disk 51 of magnetic material for attraction by the secondary clutch 46. Keyed at 52 to still another step of the jack shaft is a secondary pulley 53. Beyond the pinion 30, keyed to the jack shaft at 24, is a brake disk 54 of magnetic material secured at 55 to the pinion. This disk is for cooperation with a stationary electromagnetic brake 56 held in fixed position at 57 on the bearing 35.

Gear 6 is keyed at 60 to the crankshaft 4 and to the left of it, Fig. 4, there is a gear-pulley unit 61 having a gear 62 meshing with small gear 50 and a pulley 63 driven from the secondary pulley 53 by a belt 64. The unit 61 turns freely by roller bearings 65 on a step of the crankshaft. Unit 61 ordinarily turns opposite to the crankshaft and always turns in the same direction as the jack shaft by reason of pulleys 53 and 63 and belt 64.

Keyed at 70 to the left end of the crankshaft, Fig. 4, is a sprocket wheel 71 meshing with a chain 72 which extends upwardly to mesh with a second sprocket wheel 73 pinned as at 74, or otherwise secured to, a small cam shaft 75 rotatable in a housing 76 mounted on a support 77 secured at 78 to the loom frame. Sprocket wheels 71 and 73 are the same size so that cam shaft 75 turns at the same rate and in the same direction as the crankshaft, whether the crank shaft be turning in normal forward direction, or temporarily in reverse direction.

Mounted on the front of the loom are two boxes 85 only one of which is shown in Fig. 1. These boxes are mounted one on each end of the loom and contain certain of the switches shown in Fig. 7. Also mounted on the loom is another box 86 which contains other parts of the electric circuitry shown in Fig. 7.

When starting up the loom after a period of nonoperation switch S3, Fig. 17, will be open and electric capacitor C1 will be discharged, its charge having been dissipated through resistance D1. When the main switch for the loom motor is closed both secondary coils 87 and 88 of transformer T will be excited and coil 88 will feed current through single wave rectifier 1'12 and resistance D2 to charge capacitor C1, producing a voltage drop across relay R5 which closes normally open switch S4 via line 89, thereby connecting line 90 to the full wave rectifier 91. Current will then flow through normally closed switch S1 to excite relay R1 which via line 92 will close normally open switch S3, thus connecting line 90 to line 93. By this time, after an appreciable time lapse, such as two seconds, capacitor C1 is charged and relay R5 is no longer excited and switch S4 opens. Lines 90 and 93 will, however, remain connected through switch S3, since relay R1 remains energized. Deenergization of relay R5 permits closure of switch S6 previously held open via lines 89 and 94 when relay R6 was energized, and closure of start switch 95 in either box 85 will, through line 96, excite relay R2.

With excitation of relay R1 normally open switch 97 closes via line 99 and normally closed switch 100 opens via lines 99 and 98 When relay R2 is excited it closes normally open switch 101 via line 102 to maintain itself excited through lines 103 and 96, and also opens normally closed switch 104 via lines 105 and 106 to open the circuit between line 90 and brake 56 and also closes normally open switch 107 via lines 105 and 108 to close the circuit through line 90 and clutch 41 via line 109, switch 97 being closed. The start button can now be released, since switch 101 closes the holding circuit on relay R2. With the brake 56 off and the clutch 41 on the loom starts up and will run forwardly under normal conditions.

Under normal running conditions relays R1 and R2 are energized, line 93 is alive through switch S3, relays R3, R4, R5 and R6 are deenergized, and manually operatedbrake switch 110 is closed to connect the lower part of. line 90 to the rectifier 91.

When a weft fault occurs lever 17 is rocked counterclockwise, Fig. 1, by the dagger 13 as the lay moves forwardly and momentarily opens switch S1 and shortly thereafter closes switch S2. When switch S1 opens it breaks the circuit from line 93 through relay R1 to deenergize the latter, whereupon switch S3 opens and disconnects line 93 from the rectifier 91. Switch 101 thereupon opensand relay R2 becomes deenergized, per mitting switch 111 previously open via lines 105 and 28 to close and permitting clutch controlling switch 107 to open and break the circuit through clutch 41 and also permitting switch 104 to close to complete the circuit through brake 56 to stop the loom, switch 139 being closed. Deenergization of relay R1 also permits closure of switch 100 which results in discharge of current from the capacitor C1 through the brake 56 to stop the loom and also through clutch 41 in a reverse direction from the normal current flow derived from the rectifier, resulting in prompt release of clutch disk 39. Winding 88 thereupon attempts to recharge capacitor C1 through single wave rectifier 112, but closure of switch 100 prevents immediate recharge and the voltage drop across relay R5 energizes it with resultant closure of normally open switch S4, whereupon current flows from line 93 through now closed switch 111, wires 113, 114 and 115 through relay R6 back to the rectifier through line 116. Switch 111 is normally held open when relay R2 is alive.

Energization of relay R6 acts through line 117 to close normally open switch 118 and through line 119 to close normally open switch 120. Cam controlled switch 121 is closed at this time and will remain closed until the lay next reaches top center. Closure of switch enablescuirent to fiow from line 93 (switch S4 still being closed) through line 122 and relay R1 to line 116, thereby energizing relay R1 with resultant closure of switch S3 and opening of switch 100, whereupon the capacitor is promptly recharged and switch S4 opens. Line 93, however, is still alive through switch S3.

As lever 17 swings down it momentarily closes switch S2 which permits current to flow from line 90 through r the manually operable normally 'closed switch 110 through line 125, switch S2, line 126, relay R3, Wire 127 and cam controlled switch S to line 116. Relay R3 thereupon closes holding switch 128 via line 129 and also closes switch 130 via lines 129 and 131. As soon as relay R5 becomes deenergized normally closed switch 132, previously controlled via line 133 from relay R5, closes and a circuit is then completed from wire 93 through switches 121 and 118, wire 114, switch 130, line 134, relay R4, switch 132 and switch S5 to line 116. Relay R4, now energized, thereupon closes switch 135 via line 136 and current flows from line 93 through switch 135, line 137 and the secondary or reversing clutch 46 to line 116. Gear 51 is thereupon turned in a reverse direction and acts through unit 61 and secondary pulley 53 to reverse the jack and crankshafts. When the lay reaches its back center position cam controlled switch S5 opens and relay R4 becomes deenergized, resulting in opening of switch 135 and deenergization of the secondary clutch 46 to arrest further reverse motion of the loom. Deenergization of relay R4 also permits switch 139 to close, thereby energizing brake 56 to hold the lay at back center. The lay reverse operation is now completed and the loom is at rest with relays R1 and R2 both deenergized. The loom will remain in this condition until the weaver arrives to correct the weft fault.

'Under normal running conditions when relay R2 is energized it holds normally closed switch 111 open but when stoppage deenergizes relay R2 the switch 111 closes, whereupon current flows from it through relay R6 via wire 115. This closes switch 118 which is in series with rotary switch 121. Another result of energization of relay R6 is closure of switch 120 which provides a by-pass for switch S1. Relay R6 remains energized during the period following arrival of thelay at back center for a further reason to be described.

After the weaver has corrected the weft fault there may be no weft in the shed to support the weft fork. When either of the start buttons 95 is pushed the lay will move forwardly and the fork will fall into the well, thereby causing the dagger 13 to rock lever 17 to open switch S1 but switch 120, being closed at this time, due to continued energization of relay R6, will cancel the ordinary effect of opening switch S1, that is, loom stoppage, and the loom can therefore continue to run.

The undesired but unavoidable second rocking of lever 17 also closes switch S2which would result in unnecessary and unwanted consequences, and to avoid these means are provided to prevent this closure of switch S2 from having the usual results. Two meansare shown to cancel the effect of this second closure of switch S2, the preferred form being shown in Fig. 7, and a modified form in Fig. 9.

In Fig. 7 a normally closed switch 140 is connected via line 141 to relay R6 which will be energized at this time and will hold switch 140 open so that the righthand end of switch S2 cannot connect with line 126 and relay R3 will therefore not be energized by this second closing of switch S2. The unwanted consequences will therefore not occur. When relay R6 becomes 1 deenergized at top center, due to opening of rotary switch 121 and attendant opening of switch 120, as already mentioned, switch 140 will close for the next weft fault stopping operation, but lever 17 will have returned to its normal position with resultant opening of switch S2 before the aforesaid top center and while switch 140 is still open.

The modified form shown in Fig. 9 is manually controlled by the weaver. This figure shows only such parts of the circuit as are necessary for an understanding of the modified form and it is to be understood that all the circuitry shown in Fig. 7 will be the same except for the change shown in Fig. 9.

In Fig. 9 each of the two start buttons 95 will be providedwith a pairof top contacts 145 whieh arenqrmally connected by the switch. Awire 1 46 c onnects the two left-hand contacts 145 of the upper and lower switches 95, wire 147 connects the right-hand upper contact 145 to wire 126, and wire 148 connects the lower right-hand contact with the left-hand contact 149 of switch S2. The closure of switch S2 caused by a bona fide indication of weft fault will connect wires 125 and 126 through the contacts 145 fora desired stopping operation. When either switch is pushed to restart the loom by the weaver he will hold the switch down until the lay has reached top center, thus breaking the connection between wires and 126 to prevent closure of switch S2 by lever 17 from causing the. aforesaid unwanted consequences.

Fig. 3 and part of Fig. 2 show the collector rings which connect the 3-phase current to the electromagnetic clutches through brushes 31. These collector rings and brushes and their connection with the winding of the clutches are well known in the art and no claim is specifically made for them herein and the showing in Figs. 2 and .5 is for illustrative purposes only; It is to be understood, of course, that'a similar arrangement can, if desired, be used for the winding of brake 56. Details of the cams on shafts 75 have been omitted since cam controls of switches are well understood and it is believed that the showing in Figs. 2 and 4 together with the designations of the rotary'switches shown in Fig. 7 will be understood without further detailed description. Cams 121' and S5, Fig. 4, correspond to timer or rotary switches 121 and S5 respectively.

With further reference to Fig. 7 it may be noted-that the swtches which comprise only two nonconnected parallel lines, such for instance as switch 128, will normally be open but are closed electromagnetically under con: trol of the appropriate relay. The switcheswhich have two parallel lines crossedby a diagonal line, such for instance as switch 111, are normally closed but will be opened electromagnetically when their corresponding relays are energized. p v V z Certain matter shown in Fig. 7 is not essential to the present invention but is used as a matter of convenience. Thus, two normally closed switches are in series with switch S1 and relay R1 so that when switch S1 opens the relay R1 is, de-energized. Theseswitches may be parts of other stop means on the loom, such for instance as warp stop and protection, both electrically operated. When these other parts of the loom are in operating condition their switches will be closed and if either of their switches is open then the loom wouldbe stopped at least at the time when lever 17 can open switch S1. I From the foregoing it willbe seen that the invention sets forth means for electrically stopping theloorn on occurrence. of a weft fault and automatically reverses the direction of the jack and crank shafts to move the lay back to a position approximatingor at back center, whereupon the timer switch opens. to prevent furtherreverse movementof the loom and the brake is applied to hold the lay in its back center position until theweaver reachesthe loom. Also, when the loom is restarted after correction of the weft fault, provision is made'for preventing the unwanted opening of switch S1 and closure 'of switch S2 from having any effect on, the. loom. When the lay reaches top center position after a stoppage all the parts of the circuit are back in their normal running condition. Furthermore, the charging time for the capacitor C1 is utilized to effect a slight delay between actual stoppage of the loom upon occurence of a weft fault and the beginning of the reverse operation.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

1. In driving means for a loom having a reciprocating lay, driving means running continuously during a period assigned to loom operation, two mechanisms operably 7 connectible one at a time to said driving means to move the lay, one mechanism being connected to the driving means to drive the loom forwardly during normal operation to move the lay in usual manner for weaving while the other mechanism is in nondriving relation with respect to the loom, and the other mechanism being connectible operatively to the loom to drive the loom r'eversely when said one mechanism is in nondriving relation relative to the loom, weft stop means effective to indicate occurrence of a weft fault, and control means operatively connected between the stop means and said mechanisms effective upon indication of weft fault to disconnect said one mechanism from the driving means and automatically connect said other mechanism to the driving means to cause the latter to drive the loom reversely until the lay has been reversed to approximately its back center position, the loom having a crank shaft to drive the lay and also a jack shaft geared to the crank shaft, and said driving means includes a driven pulley loose on the jack shaft and said other mechanism includes 'a gear loose on the jack shaft to turn normally opposite to the direc tion of turning of said pulley by means partly loose on the crank shaft and partly fast on the jack shaft, and clutch means turning with the driving pulley effective to cause the latter to turn said gear to effect reversal of the jack shaft and crank shaft. 7

2. In driving means for a loom having a crank shaft operatively connected to a lay, a jack shaft geared to the crank shaft, a primary driving pulley loose on the jack shaft, :1 primary clutch to connect the pulley to the jack shaft to drive the crank shaft forwardly, a secondary pulley fast on the jack shaft, 'a gear loose on the jack shaft, a combined pulley and gear unit loose on the crank shaft having the pulley thereof belt driven from the secondary pulley and having the gear thereof in mesh with the gear loose on the jack shaft, whereby the latter gear normally turns opposite to the primary pulley when the loom is running normally, a secondary normally disengaged clutch means 'for the gear loose on the jack shaft turning with the primary pulley effective when engaged with the last named loose gear to cause the primary pulley to act through said unit and secondary pulley to reverse the jack shaft, a weft stop motion to give indication of a weft fault, and control connections between the stop motion, the primary clutch and secondary clutch effective when the stop motion gives an indication of weft fault to disconnect the primary clutch from the primary pulley and thereafter connect the secondary clutch to said gear loose on the jack shaft to reverse the latter and crank shaft to turn the lay reversely.

3. The drive means set forth in claim 2 wherein the primary and secondary clutches are of the electromagnetic type and wherein the stop motion when giving indication of weft fault opens one switch and closes another and the control connections include electric circuitry which connects said one switch to said primary clutch and connects said other switch to said secondary clutch.

4. The drive means set forth in claim 3 wherein an electromagnetic brake is provided for the jack shaft and said electric circuitry includes means to energize the brake when the indication of Weft fault is given and includes also electric means to delay energization of the secondary clutch until after the brake has been fully energized.

5. In driving mechanism for a loom havinga recipro eating lay, driving means running continuously during a period assigned to loom operation, two mechanisms operably connectible one at a time to said driving means to move the lay, an'electromagnetic element forming part of each mechanism, one mechanism being "operatively connectible by its element to the driving means to drive the loom forwardly during normal operation to move the lay in usual manner for weaving while the other mechanism is in nondriving relation with respect to the loom, and the other mechanism being operatively connectible by its element to the loom to drive the loom reversely to move the lay the reverse of said usual manner when said one mechanism is in nondriving relation relative to the loom, two electric switches one of which is for the element of said one mechanism and is normally closed and the other of which is for the element of the other mechanism and is normally open, weft stop means effective when indicating a Weft fault to reverse th normal condition of said switches, and electric circuit means connecting said switches and elements energizing the first named element only to cause said one mechanism to cause normal loom running and energizing the other element only to cause said other mechanism to cause reverse running of the loom when the weft stop means indicates a weft fault.

6. The drive mechanism set forth in claim 5 wherein the loom has an electromagnetic brake normally deenergized during loom operation but energized through said circuit means when said stop means reverses the normal condition of said switches and said circuit means includes a normally charged electrc capacitor which is discharged when the stop means indicates a weft fault, and wherein energization of the element of said other mechanism and deenergization of said brake is dependent upon recharging of said capacitor.

7. The drive mechanism set forth in claim 5 wherein the circuit means includes electric connections effective when the loom is restarted subsequent to reversing and with no Weft in the warp shed to prevent reversal of the condition of said switches by the weft stop means from stopping the loom.

8. The driving mechanism set forth in claim 7 wherein the preventing connections include a manually operable switch which prevents stopping of the loom if held closed until the lay next reaches its approximate top center position.

9. The driving mechanism set forth in claim 7 wherein the circuit means includes a third switch in series with the switch of the second mechanism and this third switch remains open until the lay reaches approximately its top center position after being restarted subsequent to a reversal of the loom.

References Cited in the file of this patent UNITED STATES PATENTS Loushin et a1. June 10, 1956 

